Gastrointestinal system

SYLLABUS:

RBP(Robbins Basic Pathology) Chapter:The Oral Cavity and the Gastrointestinal Tract

Gastrointestinal system

72 Adamantinoma

74 Pleomorphic adenoma (parotid gland)

74 Adenoid cystic carcinoma (parotid gland)

288 Chronic gastritis

184 Gastric adenocarinoma

184a Mucionous adenocarcionoma

Ulcerative colitis

Adamantinoma

Usual components in order from exterior to interior:

- fibrous stroma- basement membrane- ameloblast monolayer- "stellate reticulum" (stratified stellate cells in myxoid material)

Adamantinoma

Adamantinoma

Pleomorphic adenoma (= Mixed tumor) (parotid gland)

The dominant histologic feature is the great heterogeneity: - epithelial elements resembling ductal cells or myoepithelial cells disposed in duct formations, acini, irregular tubules, strands, or sheets of cells- well-developed ducts lined by cuboidal to columnar cells with an underlying layer of deeply chromatic, small myoepithelial cells- strands or sheets of myoepithelial cells- islands of well-differentiated squamous epithelium - a mesenchyme-like background of loose myxoid tissue containing islands of chondroid and, rarely, foci of bone

Pleomorphic adenoma

Pleomorphic adenoma

Adenoid cystic carcinoma (parotid gland)

- small cells having dark, compact nuclei and scant cytoplasm disposed in tubular, solid, or cribriform patterns reminiscent of cylindromas arising in the adnexa of the skin- the spaces between the tumor cells often filled with a hyaline material thought to represent excess basement membrane

Adenoid cystic carcinoma (parotid gland)

Adenoid cystic carcinoma (parotid gland)

Chronic gastritis

- inflammatory infiltrate of lymphocytes and plasma cells within the lamina propria- lymphoid aggregates, some with germinal centers frequently observed within the mucosa- „active" inflammation signified by the presence of neutrophils within the glandular and surface epithelial layer Additional histologic features: - regenerative change- intestinal metaplasia: the antral, body, and fundic mucosa partially replaced by metaplastic columnar absorptive cells and goblet cells of intestinal morphology- atrophy: marked loss in glandular structures- dysplasia

Chronic gastritis

Chronic gastritis

Chronic gastritis

Gastric adenocarinoma

- malignant neoplastic cells infiltrating the stomach wall

- grading based on degree of gland formation

Gastric adenocarinoma

Gastric adenocarinoma

Mucinous adenocarcinoma

adenocarcinoma with the excessive mucin production generating large mucinous lakes

Mucinous adenocarcinoma

Mucinous adenocarcinoma

Ulcerative colitis

Inflammation:- a diffuse, predominantly mononuclear inflammatory infiltrate in the lamina propria- neutrophilic infiltration of the epithelial layer may produce collections of neutrophils in crypt lumina (crypt abscesses)

Chronic mucosal damageUlceration With remission:- granulation tissue- regeneration of the mucosal epithelium- submucosal fibrosis, mucosal architectural disarray and atrophy

Ulcerative colitis

Ulcerative colitis

Ulcerative colitis